Fluoride compositions are routinely applied to teeth by any number of methods and compositions, the most common being by utilizing fluoride containing dentifrice compositions, such as toothpastes and mouthwashes.
However, there are certain situations where it is desirable to have prolonged contact of the fluoride compositions with teeth, and to use amounts of fluoride that exceed fluoride amounts present in dentifrice compositions.
For example, it may be desirable to treat xerostomia (dry mouth), tooth hypersensitivity, dental caries with high levels of fluoride for prolonged periods of time.
Thus, tooth varnish compositions have been developed, which are applied directly to tooth surfaces, for example by spray or using a brush. The film that forms upon evaporation of solvent from the tooth surface allows for a longer exposure time (e.g., about or greater than 2 hours) before the composition is worn away by mechanical means such as brushing and chewing food.
One disadvantage of tooth varnishes, and in particular tooth varnishes that contain natural film-forming ingredients such as shellac and shellac wax, is that they may in some cases have a tendency to be less than completely uniform from batch to batch, thus affecting rheological properties such as viscosity which can potentially result in uneven application of fluoride (or other active ingredient) or increased difficulty in applying the composition to tooth surfaces.
Thus, there is a need for improved tooth varnish compositions that contain appropriate synthetic materials for inclusion in tooth varnish that provide good manufacturing, application and performance properties, especially in non-aqueous tooth varnish compositions.